the biggest question is what is the end result you want from your sw
tank? full reef, fish only with live rock? what types of fish? do you plan on having other inverts such as clams or anemones? certain things require more/higher quality equipment. If its fowlr
then you can take almost any tank run a hob
filter buy some base rock and start cycling.. if you want clams youre going to want some powerful lights, anemone's usually require pristine water as well as a stable well established tank, meaning you shouldnt add them right away and probably want to run a skimmer. Certain corals are going to require better lights while soft corals will be fine with t5's or even pc
Basics are going to be tank, substrate, heater, powerhead, lights, and filter. All of those can range in price depending on what you want your tank to do. Some people use lr
as their only filter skipping the mechanical filtration, we just need more info on what you want your tank to have in it.